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Abstract
With the aging population and rising incidence of primary total joint arthroplasty has come the increasing incidence of revision total hip arthroplasties. One challenge in revision total hip arthroplasty is dealing with acetabular defects. The orthopaedic surgeon who chooses to take on these challenges requires a proper method for the evaluation of these defects as well as an evidence-based treatment algorithm. Initial assessment requires appropriate use and interpretation of imaging modalities such as x-rays and computed tomography. Preoperative planning presupposes knowledge of available approaches and implant options, such as porous coated jumbo cups, modular augments, and cup-cage constructs. Surgical execution necessitates experience in the indications for each type of implant for various types of defects. This review will aid in the understanding of each step of the diagnosis and treatment of acetabular defects in revision total hip arthroplasty.
The total hip arthroplasty (THA) gained popularity in the 1960s and 1970s with the advent of Charley's "low friction total hip arthroplasty" and has seen tremendous advances in the past 50 years. It has achieved great success with reproducible results and has been called the operation of the century.1 This has resulted in a huge number of operations performed each year. This number is consistently increasing and has exploded in recent years due to the aging of the baby boomers and our more active lifestyles. The National Inpatient Sample projects that number will increase exponentially with 575,000 THAs expected to be performed in 2030. With this, revision total hip arthroplasties (rTHA) are expected to double by 2026 as well.2-4
Prior to the adoption of polyethylene, many different bearing surfaces were tried, including Teflon and Polytetrafluoroethylene. These early bearing surfaces resulted in high wear rates, and so the rTHA was born. Delee and Charnley described their early results with polyethylene cups and revealed 69% of acetabular cups had surrounding radiolucencies, and 9% were radiographically loose at 10 years.5
Several methods were used to address the acetabular side in these early revisions. One method that was tried was re-cementation of the polyethylene cups. Amstutz and Callahan showed that 10% of cases had circumferential radiolucencies immediately postoperatively, and 34% to 71% had complete radiolucencies at midterm follow-up.6,7 The sclerotic bone in the revision setting did not allow...